
Ceiling Absorbers |
Diffusers |
Specialty Ceiling Tiles |
Wall Panels |
Noise Barriers |
ABS's of Noise Control
ABC'S of Noise Control
Absorber
Sound absorbers are soft, porous, open-celled
materials such as foam sheets or fiberglass blankets
and baffles that reduce the reflection of sound
waves. Their sound absorption efficiency is rated by
a "NRC" number - Noice Reduction Coefficient*. The
HIGHER the NRC rating, the more EFFICIENT the
product is at absorbing noise.
*NRC is a sound absorption rating. It
measures a percentage of how much sound will not be
reflected back from where it came. Based on a range
from .05 to 1.0, where a NRC of 1.0 means that all
the sound energy that hits that product passes
through it and does not "bounce" back to its source.
A NRC of .60 would reflect 40% of the sound back to
the source and let 60% of the noise pass through it.
|
|
|
Barrier
Noise Barriers combine mass, flexibility and
limpness to block noise from transmitting
from one area to another. Flexible
mass-loaded vinyl sheeting has replaced thin
lead sheets as the noise barrier of choice.
Noise Barriers are rated by a "STC" number -
Sound Transmission Classification. The
HIGHER the STC rating**, the more EFFICIENT
the product is at blocking noise.
**STC
Sound Transmission Class :
Single-number rating of airborne sound
insulation of a partition, derived by
fitting a reference rating curve to the
sound transmission loss values measured for
the 16 contiguous 1/3 octave frequency bands
with nominal mid-band frequencies of 125 Hz
to 4000 Hz inclusive, by a standard method.
The standard method typically used is ASTM
Standard E90. This test is valid for single
homogenous layers, multiple layers, or
complete assemblies. A higher STC rating
typically represents a better ability to
stop noise, frequency notwithstanding. |
|
|
Composite
Acoustical Composites are products that
combine both Noise Barrier & Sound Absorber
materials. Typically, they olffer the most
significant overall noice reduction.
Acoustical Composites are rated in both
"NRC"* and "STC"** numbers. Sound Seal uses
composite materials as Panels, Acoustical
pipe & duct Lagging or in Acoustical Curtain
Systems. |
|
|
|